I agree using the more clear icons is better.
Fixed icons for movie strips. The icon used for image strips is the same used within the sequencer. Does it need to be changed there too?
Edit: The icons have been fixed in the latest builds for 2.81 with the outliner branch merged.
Yep. The square with paint blotch was designed for the Image Editor itself. Both - the Outliner and the Sequencer must use proper Picture File pictogram.
@natecraddock - I updated the icon sheet with the Action modifier and two new Strips icons.
Are there still plans to allow custom icons?
I’ll gladly find it out for myself.
@natecraddock One more thing - Effect Strips do not have their own icons, so Outliner should use the generic Effect icon (the Magic Wand) instead of the Particle Modifier icon.
This is also fixed in the outliner branch, so builds of 2.81 have these icon fixes.
Changes in the snapping system are coming. Some of them require icons to be redesigned, since similar pictograms may be used for pop-over menu and for snapping target indication in the 3D View editor. Current design is too busy and complex for such task, so simplification is welcome.
Some sketches:
What are the new types of snapping supposed to symbolise? I recognise the older ones, but I haven’t really caught up with the recent developments yet. 
applause
From the left - Grid / Vertices / Edges / Face / Volume … Edge Midpoint / Face Center / Perpendicular to an Edge / Increments.
Which one do You like the most?
I’d go with one of two bottom rows.
this one is good, but with thin edges.
thick edges makes me mad
Thick lines are part of visual language uniform and consistent throughout the whole icon set - thick / filled means selected / important / focused on.
alright then.
took grid from first
The only icon that i dislike is the volume one, that cube with the twisted Y. It might be consistent and it might speak the icon’s language, but it barely resembles a cube to my eyes. Maybe in that case havin bold edges is not necessary? since the bold thing should be the whole object (and it already is). The Y may just be a visual hint to show the 3d nature of the pictogram. Enough text: like this
I like that little tweak, agree that the negative edges on the cube were too bold. What’s the space in the middle for ? Are we keeping this for another snap option ?
Nah - the blank space is there for pure technical reasons. Nevermind it.
BTW I just realised, that the skewed grid icon is way too similar to 3D View editor’s pictogram. I’ll use the previous ortho-version then.
Regarding @Hadriscus’ and @lsscpp’s remarks, I made bold inner edges of the cube (the Volume icon), because with thin lines the shape of the very pictogram is too much similar to the Face icon - big squarish blotch.
@jendrzych
In the tracking area.
I think that these buttons should be the same but in this way as in the green proposals. Because they do exactly the same thing only the other way around. As it is now, they seem to do different things and I find it less intuitive than my proposal. What do you think? Greetings.
The one I like the most is the last one.
Also applicable to refine markers.
this set is so awesome i wish the left toolbar had option to display bigger amount of icons like those not just few huge icons. like we have now
Are you proposing to add a unique icon for every single property and every single operator in Blender?
Just note that that would require literally thousands of icons.
Even so I’m not even sure it’s that good an idea - most apps don’t try and add icons for every single menu command or property.
@jendrzych Thank you for the Meta strip icon. It is now added to the Sequencer sidebar.